Telescoping drilling device



June 3, 1969 J. D. TIPTON 3,447,652

TELESCOPING DRILLING DEVICE Filed March 13. 1968 INVENTOR. J05 D.77Pr0/v BY ATTORNEY June 3, 1969 J. D. TIPTON TELESCOPING DRILLINGDEVICE Filed March 15, 1968 I l l l I I 1 1 It IWIME- 4 United StatesPatent U.S. Cl. 192-85 4 Claims ABSTRACT OF THE DISCLOSURE A telescopingdrill pipe assembly comprising an inner pipe, an outer pipe, and africtional hydraulically actuated coupling device for holding the twopipe members in any desired position between and including the maximumextended and collapsed positions. The inner pipe member has sleevedabout its lower end a stack of alternate resilient rings and rigid ringsadapted to be compressed by a hydraulic piston and cylinder assembly. Ahydraulic fluid supply tube extends the length of the inner pipe and isconnected to the cylinder. Pressurizing the cylinder will cause thepiston to compress the ring assembly axially thereby deforming theresilient rings radially outwardly into frictional gripping contact withthe inner wall of the outer pipe for holding the inner and outer pipesfixed relative to each other.

Background of the invention? This application is a continuation-in-partof applicants prior copending application Ser. No. 673,066, filed Oct.5, 1967, now abandoned.

Drilling devices of the type used for drilling blast holes forquarrying, mining, and geophysical exploration are usually mounted onwheeled or tracked vehicles for portability. Also, in the interest ofportability, the drill mast is limited in length and usually hinged forerection at the drill site to a substantially vertical position prior tocommencing the drilling operations. Consequently, the depth to which ahole may be drilled without adding extension lengths of drill pipe islimited by the mast height. Moreover, the use of extension pipe sectionsrequires pipe storing and handling apparatus on the mast with thepenalty of additional weight and bulk which is undesirable from thestandpoint of ease in raising nad lowering the mast.

To overcome the aforementioned problems associated with the operation ofportable drilling rigs, telescoping drilling members have been developedwhich permit the drilling of holes having a depth greater than theheight of the drill rig mast without the use of extension sections andthe associated handling equipment.

For example, US. Patent 3,255,612 issued to I. R.- Mayer and J. D.Tipton discloses a telescoping drill pipe or kelly for use with adrilling rig equipped with a rotary table drive, and which can beoperated either in the fully extended or fully collapsed condition.However, it is desirable to have telescoping drilling devices for usewith drilling rigs employing drive units attached to the top end of thedrill pipe, and it is also desirable to be able to extend thetelescoping members to any desired position intermediate the fullycollapsed or extended positions.

Summary of the invention The principal object of the invention is theprovision of a telescoping drill pipe assembly capable of being operatedand held in any position intermediate the extreme extended or collapsedpositions.

It is also an object of the invention to provide a telescoping drillpipe assembly that is simple and provides ease of operation from aremote location such as the drillers operating station, and may bestored on the mast in a collapsed condition when not in use.

A further object of the invention is the provision of an extensibledrill pipe assembly for a drilling rig having a top drive unit slida-blymounted on the drill mast which drives the drill pipe from one end only.

The invention lies in the provision of a telescoping drill pipe assemblyhaving a novel means for coupling one pipe section relative to the otherin any selected position between the totally collapsed or telescopedcondition and the maximum extended position.

The preferred embodiments of the invention contemplate not onlyretention of the inner and outer telescoping members to prevent relativeaxial movement, but also the provision of coupling means capable oftransmitting substantial torque from one member to the other withoutrotational slippage of one member relative to the other.

The hydraulically actuated resilient gripper rings form a simple andpositive locking means between the inner and outer pipe sections. Thecoupling rings are also responsive to increased axial loading of thedrill pipe to grip the pipe member with a progressively greaterfrictional force thereby being, to a degree, self-energized. Since thehydraulic actuating mechanism is essentially automatically operable, itcan be remotely controlled and requires virtually no physical effort onthe part of the drill operating personnel in order to achieve rapid andprecise positioning of the telescoping pipe members.

The novel features of the invention as well as additional objects andadvantages thereof will be understood more fully from the followingdescription when read in connection with the accompanying drawings.

Brief description of the drawings FIG. 1 is a view of a typical rotarydrill rig mounted on a tracked vehicle and employing the subjecttelescoping drilling device which is shown in a partially extendedcondition. Included in FIG. 1 is a schematic representation of a controlsystem for the hydraulically actuated coupling.

FIG. 2 is a fragmentary sectional view of a hole cleansing fluid inletpipe illustrating the components whereby the coupling pressure fluid andthe drill hole cleansing fluid are introduced to the upper portion ofthe telescoping drill pipe assembly.

FIG. 3 is a longitudinal sectional view of a portion of the telescopingdrill pipe assembly showing the torque transmitting splines.

FIG. 4 is a partial longitudinal section of the hydraulically actuatedcoupling assembly in the non-gripping condition.

FIG. 5 is a partial longitudinal sectional view of the coupling assemblyin the gripping condition.

FIG. 6 is a transverse sectional view taken along the line 6-6 in FIG.3.

FIG. 7 is a transverse sectional view taken along the line 7-7 of FIG.4.

FIG. 8 is a transverse sectional view taken along the line 88 of FIG. 4.

FIG. 9 is a fragmentary view of the telescoping drill pipes connected bya mechanical coupling.

FIG. 10 is a longitudinal sectional view of a portion of an alternateembodiment of the telescoping drill pipe assembly.

FIG. 11 is a partial longitudinal section of the hydraulically actuatedcoupling assembly of the embodiment of FIG. 10.

FIG. 12 is a transverse sectional view taken along the line 1212 of FIG.10.

FIG. 13 is a transverse sectional View taken along the line 1313 of FIG.11.

FIG. 14 is a transverse sectional view taken along the line 1414 of FIG.11.

Description of the preferred embodiments In the drawings a preferredform of the telescoping drilling device is shown as a telescoping drillpipe assembly for driving a rotary bit. In FIG. 1 the drill pipeassembly is shown in drilling position mounted on a portable drillingrig having a track laying undercarriage carrying a mast 12 which ishinged at 14 for allowing the mast 12 to be lowered to a substantiallyhorizontal position when the drilling rig is to be moved from. onedrilling site-to another. The particular type of rotary drill rigillustrated has what is commonly known as a top drive assemblycomprising a hydraulic motor 16 drivably connected to a gear box 18. Thetop drive assembly is mounted on a carrier 20 suitably retained on amechanism, not shown, but well known to those familiar with the artwhich powers the top drive assembly along the mast 12 for feeding andretracting the drill pipe assembly.

The telescoping drill pipe assembly includes an outer tubular drill pipe22 having a rotary bit 24 attached to the lower end thereof, an innertubular drill pipe 26 telescopically disposed within the outer pipe 22,and a hydraulically actuated coupling assembly generally designated by28 and explained herein later in detail.

The upper end of the inner drill pipe 26 is drivably connected to thetop drive gear box 18 by a drive coupling- 30 which is also connected tothe top drive output shaft 32.

Drill pipe stabilizers 34 and 36 are mounted on the mast 12 to journalthe drill pipe assembly and stabilize respectively the inner drill pipe26 and the outer drill pipe 22 about their axis of rotation.

Also shown in FIG. 1 is a schematic representation of a typicalhydraulic control system for actuating the coupling assembly 28 and willbe explained herein later in detail. The control system could logicallybe mounted on a drill control panel, not shown, and operated from thedrill operators platform 40.

In FIG. 2 a fragmentary section of a drill hole cleansing fluid inletpipe 42 is shown. The pipe 42 is rigidly fixed to the top drive gear box18 (FIG. 1) but is also sealably in communication with the hollow driveshaft 32. Hole cleansing fluid such as compressed air may be introducedto the interior 44 of the pipe 42 via a hose 48 (FIG. 1) from a suitablesource The hole cleansing fluid may then flow down through the hollowdrive shaft 32 (FIG. 1) and via the drive coupling 30 into the innerdrill pipe 26, down through the outer drill pipe 22, and through the bit24 for blowing drill chips from the drill hole. In applications using adown-the-hole drill (not shown) attached to the lower end of the outerdrill pipe, the hole cleansing fluid also serves as the drill workingfluid.

FIG. 2 also illustrates the means for introducing hydraulic actuatingfluid to the coupling assembly 28. A rotating union 48 of a well knowntype is disposed within the pipe 42 and the cap 50 and is also coupledto a hydraulic fluid supply tube 52 which extends through the hollowdrive shaft 32 and down through the interior of the inner drill pipe 26to the coupling assembly 28. Hydraulic fluid is thereby suitablyconducted to the coupling assembly 28 which rotates with the inner drillpipe member 26 as does the tube 52.

Referring to FIGS. 3 and 6, in a preferred form of the telescoping drillpipe assembly, driving torque is transmitted from the inner drill pipe26 to the outer drill pipe 22 through internal splines 54 on the outerdrill pipe 22 disposed to slide in complementary grooves 56 formed onthe circumference of the inner drill pipe 26. The splines 54 extend onlyover a small portion of the length of the outer pipe 22; however, tomake the inner pipe 26 fully telescopic within the outer pipe 22, thegrooves 56 extend substantially the full length of the inner pipe 26.

thetic rubber. The ring assembly is retained at the uppe end by ashoulder 70 on theinner drill pipe 26;

Threadably attached to the extreme lower end of a-sec- 0nd reduceddiameter portion 72 of the inner pipe 26 is .a hydraulic cylinder head74. A-cylinderbarrel 76 extends upwardly from the cylinder head 74 and,is affixed to the head 74.by a pin 78. An.O-ring 80 forms acircumferentialseal between the head 74 and-the barrel 76. In theannularspace formed-by the cylinder-barrel 76 surr0und.

ing the reduced diameter 72 of the inner pipe 26"is axial-J. ly slidablyhoused a piston 82 having a head 84 and: an elongated skirt 86. O-rings88 and 90 prevent leakage of hydraulic fluid past the piston head 84.The-upper end of the piston skirt 86 engages one of the metal forcetransmitting rings 64 thereby retaining the lower end coupling assembly28.

Hydraulic fluid is admitted to the cylinder by means of the elongatedtube 52 which, as previously described, extends down through theinterior 92 of the inner pipe26 from the upper end attached to therotating union 48 (see FIG. 2).

The lower end of the tube 52 is pressed into the fitting 94 which inturn is suitably secured in the cylinder head 74 as by welding at 96.Hydraulic fluid flows to the cylinder from the tube 52 through passage97, and radial extending passages 98 in the fitting 94 into a cavity 100in the cylinder head 74 and then through passages 102 and longitudinallyextending passages 104 as shown in FIG. 7. Referring to FIGS. 4 and 8,additional passages 106 are in communication with the bore 108 of thehead 74 for receiving drill holes cleansing fluid from the interior 92of the inner pipe 26 and transmitting the same to the interior 110 ofthe outer drill pipe 22.

In the deenergized condition of the coupling assembly 28, as shown inFIG. 4, the resilient coupling members.

66 have an outside diameter 67 slightly less than the inside diameter ofthe wall 69 of the outer drill pipe 22 so that the inner and outerdrilling members are .free to slide.

FIG. 5 illustrates the energized condition of the coupling assembly 28.Hydraulic fluid underpressure acting against-the piston 82 willcauseaxial displacement and forceable engagement against the first forcetransmitting ring 64 and successive transmittal of force through eachresilient ring 66 causing elastic deformation as shown so that eachresilient ring 66 fills the annular spaceformed between each forcetransmitting ring64, the outer diameter 68 of the inner drill pipe.26,-and the. inner wall 69 of the outerdrill pipe 22. Particularlysignificant in the embodiment shown is thatthe outer-diameter 67 of eachresilient ring 66 is now inpositive engagement withthe inner wall 69 ofthe outerdrill pipe 22 thereby establishing at riction coupling betweenthe inner. pipe-26 and the outer pipe 22 preventing longitudinaldisplacement of; one.

relative to the other even .under a substantial, axial load. I

In fact, a degree of self-energization is experienced'due to the factthat an increase in axial force on the inner drill pipe 26 tends tocause additional elastic deformation-of the rings 66 and resulting ingreater forces exerted on the pipe wall 69 which establishes greaterfrictional resistance to axial displacement of the inner pipe 26relative .to-

the outer pipe 22. 1

The frictional holding force of the coupling assembly is also.proportional to the area of contactbetween the resilient rings 66 andthe wall 69 so that increasing the of the l total number of rings willincrease the holding capacity of the coupling assembly. By way ofexample, a coupling assembly having a total of twelve synthetic rubberrings one inch long used on a 3.75 inch diameter drill pipe as semblywill support an axially applied force on the inner drill pipe sufiicientto raise a typical drilling rig on the ground at the mast end of theundercarriage.

In operation, drilling would begin with the inner and outer pipe membersin the fully telescoped condition. The coupling assembly 28 would beenergized by operating a control valve 112 (FIG. 1) to valve hydraulicfluid from a supply pump 113 mounted on the drill rig through conduits114 and 116, a pilot operated check valve 118, and conduit 120 to therotating union 4'8 and supply tube 52. An axially applied drill feedingforce from the top drive carrier 20 could then be transmitted from theinner pipe 26 through the coupling 28 to the outer pipe 22, to putsufiicient pressure on the bit 24 for effective drilling.

After drilling the maximum depth in the telescoped condition, thecontrol valve 112 would be operated to deenergize the coupling bysupplying hydraulic fluid via the pump 113 to the conduit 122 and thecheck valve pilot operator 124 to open the check valve 118. Hydraulicfluid would then be forced out of the coupling assembly 28, via conduits120, 116, and 121, to the sump 126, as the resilient rings 66 resumedtheir relaxed condition of FIG. 4. The top drive carrier 20 could thenbe operated to pull the inner drill pipe 26 up the mast 12 at least thedistance equal to the additional depth of hole desired while the outerpipe 22 would remain in the hole due to its own weight. After againenergizing the coupling assembly 28, as described, drilling operationscould be resumed with the inner and outer pipe members securely coupledin an extended position.

At the completion of drilling operations the extended assembly iswithdrawn from the drill hole by raising the carrier 20 up the mast 12until a grooved portion 130 near the top end of the outer drill pipe 22is just above the lower stabilizer 36. In this position a somewhatC-shaped retaining member (not shown) is inserted in the grooved portion130 and also rests on the stabilizer 36 thereby supporting the pipe 22when the coupling assembly 28 is deenergized. The drill pipe assemblycan then be collapsed and after energizing the coupling assembly 28,once again, the telescoped pipe assembly can be withdrawn completelyfrom the hole.

In the event of hydraulic supply pressure failure, or a seal failure inthe coupling assembly, the outer drill pipe 22 could be withdrawn fromthe hole by collapsing the drill pipe assembly until the groove 128 onthe inner drill pipe 26 was adjacent the grooved portion 130 on theouter drill pipe 22 whereupon as shown in FIG. 9, a mechanical coupling132 could be inserted in the grooves to couple the drill pipes forraising or lowering the telescoped assembly.

In the aforedescribed embodiment it can be appreciated that due to thefact that elastic deformation of the re silient rings 66 causes them tofrictionally grip the reduced diameter portion 68 of the inner drillpipe 26 as well as the inner wall 69 of the outer pipe 22 the couplingassembly could be used to transmit a limited amount of driving torquesuch as required for rotary indexing of percussion drills anddown-the-hole type drills.

An alternate embodiment of the telescoping drill pipe assembly isillustrated in FIGS. through 14. Referring particularly to FIGS. 10 and11, portions of an outer tubular drill pipe 222 are shown telescopicallydisposed over an inner tubular drill pipe 226. The outer drill pipe 222has a grooved portion 230 near the top end serving the same purpose asthe grooved portion 130 of the drill pipe 222. The top end of tubularpipe 222 has a cap 223 threadedly disposed thereon. The cap 223 houses acircumferential sealing member 225 in a groove 227. The sealing member225 functions to prevent drill chips and dust from falling down into theannular space 229 between the inner and outer drill pipes when the topend of the outer drill pipe is below ground level. The lower end of theouter tubular drill pipe 222 (FIG. 11) terminates with a threaded sub258 having a plurality of holes 260 for conducting pressure fluid forhole cleaning when using a drilling tool (not shown) such as a rotarybit, or for energizing a down-thehole drill attached to the sub 258.

In FIGS. 10 and 11, the lower end of the inner drill pipe 226 is shownwith a hydraulically actuated coupling assembly 228 attached thereto.The coupling assembly consists of a plurality of alternately stackedmetal force transmitting ring members 264 and resilient ring members 266disposed on a reduced diameter portion 268 of the inner drill pipe 226.As shown in FIG. 10, the reduced diameter portion 268 may be formed as aseparate member and suitably fastened to the inner drill pipe 226 suchas by welding at 271. As shown in FIGS. 10-14, the reduced diameterportion 268 has straight sided splines 273 for engaging complementarygrooves in the force transmitting rings 264 and the resiilent rings 266.The ring assembly is retained at the upper end of the reduced diameterportion 268 by a shoulder 270.

Threadably attached to the extreme lower end of a second reduceddiameter portion 272 of the inner pipe 226 is a hydraulic cylinder head274. A cylinder barrel 276 extends upwardly from the cylinder head 274and is aflixed to the head 274 by welding at 278. In the annular spaceformed by the cylinder barrel 276 surrounding the reduced diameter 272of the inner pipe 226 is axially slida-bly housed a piston 282 of thesame configuration as the piston 82. The upper end of the piston 282engages one of the metal force transmitting rings 264 thereby retainingthe lower end of the coupling assembly 228.

Hydraulic fluid is admitted to the cylinder by means of a flexibleelongated tube 252 which, as in the embodiment of FIGS. 1 through 9,extends down through the interior 292 of the inner pipe 226.

The lower end of the tube 252 terminates in a threaded connector 293which is pressed into a fitting 294. The fitting 294 is suitably securedin the cylinder head 274 by a retaining ring 296. Hydraulic fluid flowsto the cylinder from the tube 252 through passage 297, and radialextending passages 298 in the fitting 294 into a cavity 210 in thecylinder head 274 and then through passages 202 and longitudinallyextending passages 204 as shown in FIG. 11. Additional passages 206 arein communication with the bore 208 of the head 274 for receivingpressure fluid from the interior 292 of the inner pipe 226 andtransmitting the same to the interior 211 of the outer drill pipe 222.

The operation of the coupling assembly 228 is similar to the couplingassembly 28 previousl described. However, as will be noted from FIGS. 10and 12, the complem'entary torque transmitting splines and grooves havebeen eliminated from the outer drill pipe 226 and the inner drill pipe222, respectively. In the energized condi tion (not shown) of thecoupling assembly 228, the axial compressive force exerted on thestacked rings by the piston 282 will cause the resilient and elasticallydeformable ring members 266 to deform radially to frictionally grip theinner wall 269 of the outer drill pipe 226. Due to the fact that theresilient n'ngs 266 are splined to the inner telescoping drill pipe andare in frictional engagement with the metal force transmitting rings 264over respective transverse surfaces 283 and 285, the coupling assembly228 is able to sufficiently transmit all the torsional effort requiredin rotary drilling as well as maintaining the fixed axial relationshipof the inner and outer telescoping members.

In the embodiment of FIGS. 10 through 14, the resilient ring members 266can be suitably made of a polyurethane elastomer of approximately -100durometer hardness. Replacement of worn rings is facilitated byproviding a radial split 299 in the rings 266 (see FIG. 13) to enablethe rings to be forcibly spread for insertion over and removal from thereduced diameter portion 268 without complete disassembly of thecoupling.

Although in the embodiments described herein the illustrative drillingrig is a top drive rotary rig, it will be appreciated that the inventioncould be used to equal advantage with various types of drillingequipment such as percussion, down-the-hole, and auger drills to extendthe depth of hole drilled without resorting to adding and removingextension drill string members.

What is claimed is:

1. In a drilling device including drive means for rotating a drill pipe,a telescoping drill pipe assembly com prising:

(a) an elongated outer tubular member having attachment means adjacentits lower end for attaching a drill bit or the like;

(b) an elongated inner tubular member operable to be rotatively drivenby said drive means and dimensioned for longitudinal telescopic movementwith respect to said outer tubular member; and

(c) frictional coupling means mounted on said inner tubular memberadjacent the lower end thereof for telescopic movement therewith andoperable to releasably couple said tubular members in fixed longitudinalrelationship, said coupling means comprising:

(1) at least one elastically deformable ringlike member surrounding saidlower end of said inner tubular member, said ringlike member in itsnondeformed condition being movable with respect to the inner wall ofsaid outer tubular member and in its deformed condition being infrictional gripping engagement with said inner wall of said outertubular member; and

(2) pressure fluid operable actuator means attached adjacent said lowerend of said inner tubular member, including cylinder and pistoncomponent means, one of said component means being extendable inresponse to operation of said actuator means to deform said resilientmember into frictional gripping engagement with said inner wall of saidouter tubular member thereby to hold said outer and inner tubularmembers in fixed longitudinal relationship.

8 2. The invention set forth in claim 1 wherein: said ringlike member inits nondeformed condition being movable with respect to the outer wallof said inner tubular member and in its deformed condition being infrictional gripping engagement with said outer Wall of said innertubular member, whereby, in response to operation of said actuatormeans, said inner tubular member and said outer tubular member are heldagainst relative rotation. 3. The invention set forth in claim 1wherein: said coupling means includes at least one substantially 'rigidringlike force transmitting member surrounding said lower end of saidinner tubular member and engageable with said elastically deformablemember over respective transverse surface means, said lower end of saidinner tubular member includes longitudinal external splines formed onits outer wall, said ringlike members include complementary grooves forengaging said splines, and in response to operation of said actuatormeans said resilient member is forced into frictional grippingengagement with said transverse surface means on said rigid memberthereby to hold said outer and inner tubular members against relativerotation. 4. The invention set forth in claim 1 wherein: said outertubular member includes inwardly projecting longitudinal spline membersdisposed on its inner wall and said inner tubular member includescomplementary longitudinal grooves disposed in its outer wallwhereby-said outer tubular member is operable to be rotatively driven bysaid inner tubular member.

9/1962 Gidge. 12/1964 Baver et a1 285338 X 40 BENJAMIN W. WYCHE, III,Primary Examiner.

U.S. C1. X.R.

